Automobile heater



April 1, 1941 H. J. DE N. MccoLLUM-ETAL AUTOMOBILE HEATER Filed 0G12. 10, 1938 2 Sheets-Sheet l April 1, 1941'- H. J. DE N. mLLuM Erm. 2.236.789

AUTOMOBILE HEATEK Filed oct. 1o,v 1938 2 Sheets-Sheet 2 mmf.

Patented Apr. 1, 1941 AUTOMOBILE HEATER Henry J. De N. McCollum, Evanston, and Thomas F. Spackman, Chicago, Ill.

Application October 10, 1938, Serial No. 234,136

Claims.

The invention relates generally to heaters for motor vehicles, and more particularly to those for use with vehicles having large riding compartments, such as buses, trailers, and the like.

An object of the invention is to provide an internal combustion heater of the class described wherein dual carburetion and dual combustion are carried on in a single device. l

Another object of the invention is to provide an internal combustion heater of the class de- -scribed having dual .combustion chambers wherein ignition of a combustible mixture in one of the chambers is utilized to ignite the mixture in the other chamber.

Another object of the invention is to provide an internal combustion .heater of the class described wherein ignition of the combustible mixture in dual chambers mutually support each other and each is ignited by the other when extinguished.

Another object of the invention is to provide an internal combustion heater of the class` described wherein a plurality of generators are subjected to approximately identical factors and the ignition in one generator is employed to initiate combustion in all.

Another object of the invention is to provide a large capacity internal combustion heater of the class described which automatically reduces the amount of exhaust gases entering the intake manifold of an internal combustion engine when the engine is idling.

Another object of the invention is to provide an internal combustion heater of the class described employing multiple heat generators which is simple in construction and operation, eective in use and inexpensive to manufacture and operate.

These being among the objects of the invention, other and further objects will become apparent from the drawings herein, the description relating thereto and the appended claims.

Referring now to the drawings:

Fig. 1 is a top plan, partly in section, illustrating the preferred embodiment of the invention.

Fig. 2 is a yside elevation, partly in section, of the construction shown in Fig. 1.

Reference may be had to the co-pending application of Henry J. De N. McCollum, Serial No. 61,213, lled January 28, 1936, for a, description 'of certain details of the present invention relating to mountings, carburetion and the general features of heater construction wherein, brieily, a

casing I0 is secured by brackets I2' to the dashboard |4` of a motor vehicle within the passenger compartment thereof, and a motor I6 driving a fan I8 is employed to circulate air'over a radiator construction 20 which is supplied with heat generated from combustible mixtures as developed by carburetion and ignition under the influence of vacuum created by the engine of an automobile.

In the present invention the heater comprises asingle casting with two separate combustion chambers A and B formed therein which are connected by a direct and open4 passageway 46. Equal increments of combustible mixtures are supplied to the combustion chambers independently of.each other. In the'embodiment illustrated, two identical carburetors 24 are employed for this purpose.

Fuel for the carburetors 24 is supplied through tubes 30 leading from the oat bowl of the engine carburetor (not shown), and the fuel mixed with air in the carburetors is fed to the combustion chambers A and B through tubes 32 which are pressed into the passageways 34 formed in the extensions 36 of the casting 22. A baille plate 38 of suitable heat resisting material is located in each of the combustion chambers adjacent the open ends 4Q of the tubes 32. The tubes 32 project into the combustion chambers and the mixture of the gasoline and air is distributed fairly evenly throughout the chambers because of the turbulence developed by impact with the bale plates 38. During operation, after combustion is under way for both units, each tube 32 and baille plate 33 become hot and pre-heat the fuel and gas mixture and through conductivity of the metal casting 22 heat is carried back to approximately the inlets of the carburetors 24 to assure proper mixture of the combustible elements.

Opening into the combustion chamber A is a secondary chamber 42 provided in the casting 22. An igniter 44 is mounted in the secondary cham: ber 42 and upon the side of the combustion chamber A opposite the igniter 44 is the opening of the passageway 46 which connects the two combustion chambers. A clean-out plug is provided in the wall of combustion chamber B for the passageway 46. Reigniter plugs 48 madeof a slightly porous refractory ceramic material are held in suitable sockets formed in the ends of the combustion chambers. The plugs 48 are provided with a plurality of longitudinally extending passageways of relatively small diameter and have a recess 50 at the center, yopening into the combustion chamber, to provide a hot spot where the combustible mixtures tend to collect for a long enough time to become heated to a temperature necessary to cause ignition.

After combustion takes place, the resulting hot gases ow into separate radiator units 26a and 26h. The radiator units, respectively, are provided with tortuous passageways 28a. and 28h of substantially the same length which join at a common outlet 49. Thus, the products of combustion do not intermingle until they approach the outlet 49 except through the passageway 46 as hereinafter described. At the outlet 49, the gases are drawn off through the tube I to the intake manifold of the automobile engine, and a compensator 52 having a Venturi-shaped restriction 53 regulates and maintains substantially constant the flow of gases from the radiator 26 regardless of wide variations in the degree of vacuum developed in the intake manifold.

Thus, the vacuum but are also substantially constant for both units when both units are operating under identical conditions as when combustion is taking place in both units or combustion is not present in either unit. In either event there will be no exchange of gases through the passageway 46. However, a flow of gases from one combustion chamber to the other will take place when the vacuum facto'rs are not equal for both units.

In the embodiment shown, such an unbalance is brought about automatically when one of the units is in operation While the other is extinguished. Combustion of one of the two equal increments of combustible mixture supplied to both units separately creates a larger effective volume of gas in one unit, due to combustion and heat expansion factors, as compared with the unburned increment in the other unit. This larger volume of gas in the burning unit relieves the vacuum exerted in that unit and in conjunction with the relatively higher degree of vacuum existing in the other unit, hot gases and ame will flow through the passageway 46 from the ignited chamber to the idle chamber, it being understood that the length of the tortuous passageways 28a and 28h and the relative speed of gases flowing through them will retard a balancing of relative pressures in the units through the common outlet connection long enough for the flow of gases and flame through the passageway 46 to take place. This flow of gases and iiame ignites the combustible mixture supplied the idle chamber and establishes combustion in both chambers A and B.

In controlling the amount of gas permitted to ow from the two units to the intake manifold, a concentrically acting double member valve is employed, each member of the valve acting and operating independently of each other. A thick walled tubular member 661s slidably mounted in the radiator 20 in axial alignment with the mouth of the Venturi-shaped passageway 53 of the compensator 52. The end of the tubular member 60 engaging the compensator is shaped tomate with the mouth of the passageway 53 in sealed relation and at the other end of the member 20 a U-shaped spanning member 62 connects the member with the handle 54 for manual movement of tubular member 60 from and to its sealed relation with the compensator 52.

A rod 64 slidably mounted in the tubular member 60 provides the second member of the valve. The diameter of the rod is appreciably less than the diameter of the Venturi-shaped passageway 53 at its neck. At one limit of movement the rod factors are not only'equal,`

enters the neck of the passageway and at its other limit clears the compensator so that the ilow of gases therethrough is unrestricted.

For operation ofthe rod 64, the end thereof remote from the compensator terminates between the walls of the U-shaped member 62 where the rod is fastened to one arm 66 of a bell-crank which is actuated by a vacuum-responsive member 66 and to which the bell-crank is connected by a linkage comprising rods 16 and a second bell-crank lever 12. The vacuum responsive member 68 is connected to the carburetor 16 adjacent the throttle valve 18 through a tube 14. The port 19 in the carburetor is so located that when the throttle valve 18 is nearly closed, as in the dotted line position A, the pressure at the port is substantially atmospheric, but when it is moved to the dotted line position B, the vacuum at the port 19 is high. Thus, the operation of the vacuum responsive device 66 is very sensitive to the position of the throttle valve in its nearly closed position. The bell crank levers are positioned to force the ,rod towards the compensator 52 when the vacuum in the intake manifold of the engine approaches its highest degree. In this way the iiow of burnt gases into the manifold from the large capacity heater is restricted to prevent engine faltering at idling or low speeds.

In operation, the heater is turned on by manipulating the handle 54. The igniter coil 44 is energized thereby and the mixture of the combustible elements entering the combustion chamber A are ignited. The hot gases thus developed have two places to go, either into the unit 26a or through the passageway 46 into the combustion chamber B. Since, however, more gas per volume is being developed in the combustion chamber A than in the idle combustion chamber B, a flow of naming gases through the passageway 46 to establish combustion in chamber B results as already explained.

In this way, once A is ignited and warm air begins to ow into the unit 26a, the effective vacuum in the two combustion chambers will be greater'in combustion chamber B than in the combustion chamber A, and the flame will be vdrawn over through passageway 46 to ignite the combustible elements in the combustion chamber B, after which B will continue to burn more or less independently of A, the vacuum factors being equalized between the units and the two combustion chambers once both are in full operation.

In event the combustion in either one of the chambers becomes extinguished, the one, whether it be A or B, which becomes extinguished, will begin to cool as accelerated by vapor-ization of the combustible mixture, and the combustible mixture flowing therethrough will constitute a cooling agent which will create unequalized vacuum factors between the two combustion chambers, at which time flame will be supplied through the passageway 30 from the combustion chamber having the continuous flame to the other, so that the' other which has been extinguished may be reignited.

Thus a single igniter coil is used to start combustion in both chambers and need not be used thereafter as long as combustion is maintained in either chamber. Thereby a saving in electricity and a simplification in circuits involved in the control of the heater is accomplished. Moreover, the complexity of the casting is reduced and a heater may be f provided with additional larly adaptable for large installations such as trailers and buses, cabin cruisers and transport planes, and, although a single embodiment of the invention has been shown and described in the accompanying drawings, it is apparent to those skilled in the art that various other and further uses, modifications and changes may be made in the construction as shown, without departing from the spirit and substance of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

l. An internal combustion heater for motor,

vehicles comprising a plurality of heat exchange units having circuitous passageways joined at a common outlet, a unitary casting having a plurality of enclosed combustion chambers for said units respectively, means for supplying said combustion chambers with combustible mixtures, means for igniting the mixture in one chamber, conduit means extending through said casting and connecting said chambers to carry combustion from one chamber to another, a conduit in communication with' the intake manifold of an internal combustion engine and forming a common outlet for the heat exchange units through which said units` are subjected to the varying degrees of vacuum in the intake manifold for withdrawing gases from the units, compensator means in said conduit having a restricted passageway, manually operated means for opening and closing said passageway, and vacuum responsive means for further restricting said passageway responsive to variations in the degree of vacuum in the intake manifold.

2. A large capacity internal combustion heater for motor vehicles comprising a plurality of heat exchange units having a common outlet con-- nected to the intake manifold of an internal combustion engine, means for supplying said units with hot products of combustion, compensator means at said outlet having a restricted passageway, manually operated means for opening and closing said passageway and vacuum responsive means for further restricting said passageway when the degree of vacuum in said intake manifold is high.

3. An internal combustion heater for motor vehicles comprising, a plurality of heat exchange units, a unitary casting providing a plurality of enclosed combustion chambers for said units respectively, separate means for supplying each of said combustion chamberswith a combustible mixture of liquid fuel and air, means for igniting the mixture in one of said chambers, conduit means connecting said chambers to carry combustion from one chamber to another, a conduit in communication with the intake manifold of an internal combustion engine andforming a common outlet for said heat exchange units, and means in said conduit for restricting the ilow of gases from the heat exchange units when the degree of vacuum high.

4. An internal combustion heater for motor vehicles comprising a pair of heat exchange units,

a conduit forming a common outlet for said heat exchange units and communicating with the intake manifold of the internal combustin engine for subjecting the heat exchange units to differential pressures to cause ow of gases therethrough, a unitary casting providing a pair of combustion chambers for said units respectively, means individual to each of said combustion chambers for supplying a combustible mixture thereto, means for igniting the mixture in one of said chambers, and conduit meins connecting said chambers and effective to carry combustion from either chamber to the other.

5. An internal combustion heater for motor vehicles comprising a heat exchange unit having a passageway extending -therethrough and terminating in an outlet, a manually operable valve effective to close said outlet, a rod extending through said valve and movable with respect thereto, said rod being capable of beingprojected from said valve into said outlet to restrict the latter, means-responsive to a high vacuum for moving said rod relative to said valve into a position to restrict said outlet and a variable source of vacuum for actuating said vacuum responsive means.

4 HENRY J. DE N. McCOLLUM.

THOMAS F. SPACKMAN.

in the intake manifold is 

